This toolbox can be opened via the Window > Standard Toolboxes menu.
Keyboard Entry Toolbox
Entering values into the toolbox is equivalent to picking points on the project (enter the X value, press Enter, enter the Y value, press Enter).
The Keyboard Entry toolbox can be used in conjunction with any tool that requires a point to be picked. This allows you to input offset distances or coordinates.
You can use the toolbox in absolute mode, entering positions in the current coordinate system, or in relative (that is, incremental) mode, entering a position relative to the last point entered (or picked).
Press the appropriate button 
or 
to switch between modes.
The two main input boxes are displayed as:
"X" and "Y", if you are using absolute Cartesian coordinates
"dX" and "dY", if you are using relative (incremental) coordinates
"R" and "A", if you are using absolute polar coordinates
"dR" and "dA", if you are using relative (incremental) polar coordinates
Press the Cartesian 
or Polar 
button as required to select the coordinate system.
The Toggle more/fewer options button 
is used to hide or display the Absolute/Relative and Cartesian/Polar buttons.
Activate the drawing tool you require then activate the keyboard entry tool. If the toolbox is displaying coordinates in the mode you require, type a value in the first input box and press Enter. The focus moves to the second input box. Type a value here and press Enter once more. The drawing tool reacts as if you had picked a point on the project.
The Keyboard Entry toolbox remains on display until you close it. It can be used in conjunction with any tool that requires a point to be picked. At any time you can alternate between this mode of entering coordinates and directly picking points on the project.
You can use the keyboard to identify a point offset from a snapped point on the current canvas. Select the correct snap mode and hold down the Control and Shift keys and pick a point on the current canvas. This will place the focus on the first input box of the toolbox. The values input will be offset from the snapped point. The Relative to coordinates will be those of the snapped point.
Related topics: Notes On Standard Toolboxes.